CURRENTLY USING NUTRITIONIST AND CDMAS ONLY. A randomized placebo- controlled crossover study in healthy adults designed to study the underlying serotonergic alteration in OSA and the 5-HT system in controlling ventilation in humans. Specifically, the study will be divided into two periods: 1) normal brain serotonin period, produced by a carbohydrate-protein balanced diet; and 2) depleted brain serotonin period, produced by a tryptophan-deficient diet. In each period the effects of these diets on ventilatory variability will be measured. The research nutritionist and systems manager have had key roles in the development of the sections of this project related to their expertise.